Process of making color-screens.



0. 's. DAWSON & 0. L. FINLAY.

PROCESS OF MAKING COLOR SCREENS.

APPLIGATION FILED APR. 11, 1910.

Patented Feb. 3, 1914..-

'rnn STATES rA EEN'r @FFICE.

OLIVER SAMUEL DAWSON AND CLARE LIVINGSTONE FINLAY, OF HIGBI HOLBORN,

LONDON, ENGLAND, ASSIGNORS TO GEORGE FREDERICK RIMELL BAGULEY, OF

Lennon, ENGLAND.

PROCESS OF MAKING COLOR-SCREENS.

Patented Feb. 3,1914.

Application filed April 11, 1910. Serial No. 554,856.

specification.

The specification or British Patent No. 19652 of 1906 granted to one ofus describes a generally satisfactory method of multicolored screenmanufacture according to which difi'erently colored series of dotsofmicroscopic. dimensions and of curvilinear outline are produced indefinite order and sequence one to another and to a differently coloredinterspacial filling. 'Notwithstand ing the combined minutencss,intimate proximity and orderly disposition of. the

,color elements, diflerent screens cannot be interchanged Without lossofadvantage or efiect where accurate registration is important, as in highclass duplicating and like work such as using difierent screens forrespectively taking and viewing or projecting. Such. lack ofinterchangeability re sults from the rearranging, in the describedprocedure, of the relative positionof a suit-- able dot yielding plateand the screen, between the production of each dot series whereby eachshall appear in its proper relative position. Each screen is per sewholly satisfactory, but different ones are not, as regards their colorelements, positionally identical and are therefore non-registrable.

This invention has for its object to obviate this disadvantage. A colorscreen made according thereto comprises several series of dots ofsubstantially curvilinear outline and a complementary filling eachtransparent-and differently colored and all of Making Color- Screens, ofwhich the following is a.

quent in practice, such areas are equal or substantially equal.

According to one method of carrying out the invention'a foundation plateis produced capable of yielding a representation on the color screensurface of the portion corresponding to the filling and, for use in-'ccnjunction with said plate, another or supplementary plate, resultingfrom a stage in theproduction of the foundation plate, and capable ofprecisely registering with any one of the dot series, either on thecolor screen or its counterpart on the foundation plate. These twoplates can be used for producing an unlimited number of color screenswhose respective color elements are in identical positionalrelationship.

In the accompanying illustrative. drawings, Figures 1 to 4 respectivelyshow diagrammatically in exaggerated form, the character of plates orimpressionsoccurring in the production of the foundation plate and Fig.5 similarly represents an impression yielded by such foundation plateand forming the basis of a color screen.

A plate as A (Fig. 1) is obtained photographically from a Levy crossline screen by utilizing screen distance and a small circular stopin thecamera and comprises symmetrically arranged opaque circular dots orpatches A collectively occupying one third -or thereabout of the platearea, the remainder being transparent. Treating plate A as a negative, apositive, as plate B, (Fig. 2) is photographically produced therefromand comprises circular transparent spaces occupying one third orthereahout of the plate area, the remainder being opaque. Such plate Bis the supplementary plate.

Plate B is caused to photogra hically yield a further negative, as plateC Fig. 3), come prising, as plate A, circular opaque dots,

termed for distinction C of similar total area and a transparentremainder. Plate Cv is again sensitized, and plate B accuratelysuperposed so that the circular spaces of the latter are intermediateand geometrically symmetrically so, of the dots of plate C.

Exposure and developmentyiclds a plate D,

(Fig. l) comprising opaque images of both the dot series A and Ctogether occupying two thirds or thereabout of the plate area andatransparent remainder or interspacial portion. Such a plate constituteswhat is herein called the foundation plate. Color screens can beobtained by the aid of the said foundation and supplementary plates asfollows :A suitably sensitized transparent support, glass orcelluloidfor instance, is

exposed through plate D so as to yield a practically transparentimpression of the interspace or filling shown shaded in Fig. -5

I series, say S and the inter-space or filling 1 fillings and beingmasked by the opaque remainder of plate 13. An impression is thenobtained in the ordinary way and afterward dyed with its appropriatetransparent color. The transparent support is now sensitized for thethird time, and exposed throu h the back, thus yielding an impression ofhe second set S of circular spaces which are afterward dyed with theremaining appropriate transparent color. Each color is protected as laiddown so as to prevent its being affected by any later row-dyeingoperations. screen thus produced can either form an integral part of asensitive plate or film, orit can be used in conjunction with or inproximity to such aplateorfilm, whether for taking, viewing, projecting,or duplicating photographic impressions in colors.

What We claim is 1. In the art of producing regular pattern colorscreens comprising differently colored series of spots havingsubstantially curvilinear outline and complementary filling in contactwith but not overlapping said spots, consisting in producingphotographically upon the surface intended to form the color screen animpression of said complementary then producing in the vacant spaces ofsaid filling a. photographic impression of non-overlapping spots.

2. The method of making a color screen having non-overlapping colorareas said areas having geometric symmetrical relationship, said methodconsisting'inphotographically producing on a transparent sup.- port afilling affording spaces having cur-- vilinearoutlines and then layingdown color spots contacting with but not overlapping the outlines ofsaid filling.

3. The method of making a color screen having non-overlapping colorareas, said areas havin'g geometric symmetrical relationship, saidmethod consisting in photographically producing a foundation plateprovided with opaque lot series and a suppattern color screens of thekind A color carrier producing on the the herein described improvementplementary plate having an opaque filling adapted to exactly reg'sterwith any one of saiddot series, then printing ona sensitized colorscreen plate with said foundation plate to produce a filling in onecolor and then printing on said screen with said supplementary plate toproduce dots in a difierent, color exactly contacting with said filling.it. The process of manufacturin regular escribed, which consists inproduciiig photographically upon the surface intended to form the colorscreen an impression that will be complementary to series of spots ofcircular form and then producing impressions of each such spot series. 7

In the art of producing regular pattern color screens of the kinddescribed, the herein described improvement consisting inphotographically producing on transparent material an opaquerepresentation of a series of the required spots having substantiallycurvilinear outline, obtaining therefrom a' corresponding negative, fromsaid negative producing on a transparent carrier opaque composite imageof a plurality of spot series and from the resulting image on saidcarrier producing on the'surface intended to't'orm thecolor screen anon-opaque impression of the portions of saidcomposite imageintermediate ofthe spot series.

6. In the art of producing regular pattern color screens ofthe kinddescribed the herein described improvement consisting. in"photographieally' producing on transparent material an opaquerepresentation of a series of the required" spots having-substantiallycurvilinear outline, obtaining therefrom a corresponding negative fromsaid negative, producing, on a transparent carrier an opaque compositeimage of a plurality of spot series, from the resulting image on saidspnarface intended to form the color screen a n sion of the portions ofsaid composite image intermediate of the spot series, coloring the imageof said impression, and after re-sensi-' tizing the said surface,employing said nega- 'tive to admit light to the portions corre-fspending to one spot series and mask the remaining spot series andintermediate fill} ing and afterward appropriately coloring the thusproduced image of the said spot series. v I

7. The herein described improvement in the art of producing regularpattern dolor screens of the kind described, consisting inphotographicallyproducing on transparent material an opaquerepresentation ofa series of the required spots having substantiallycurvilinear. outline, obtaining therefrom a corresponding negative, fromsaid negative producing on a transparent carrier an opaque compositeimage of a plurality of spot series. from the resulting image oni'said'n-ppaque imprespression'of the portions image intermediate of the spotseries,

carrier producing on the surface intended to form the color screen anon-opaque 1111- of said composite ing the image of-seicl im ression andafter re-sensitizing the said sur aee em loying the said negative toadmit light to tii corresponding to one spot series and mask theremaining spot series and intermedisit? filling, afterward appropriatelyeol'oring the 'thusprodnced image of the said. spot series,

c'olore portions re-sensitizing the surface, exposing the last series tolight through the back of the screen and coloring the image produced.

Signed at London of March 1910.

. OLIVER SAMUEL DAWSON.

CLARE LIVINGSTONE FINLAY.

Witnesses:

RIPLEY WILSON, R. F. W ILLIAMS.

Engliind this 14th day 15

